In the IEEE 802.3u, standard section 22, the Media Independent Interface (MII) is a standard interface that connects Media Access Control (MAC) sublayer device to a physical (PHY) layer device. The MII allows the same MAC device to be connected onto different physical layers.
FIG. 1 shows a first embodiment of a conventional repeater system 10. Although not explicitly stated in the IEEE 802.3 standard, the MII is commonly used to connect repeater devices onto various different physical layer devices.
The repeater system 10 of FIG. 1 includes a repeater 12 which includes a repeater core 14 which is in turn coupled to a plurality of PHY devices 16. The PHY devices 16 in turn are coupled to an associated data terminal equipment (DTE) 18. Typically, each of the DTEs 18 include serially connected PHY and MAC devices 17 and 19, respectively.
In a typical configuration the repeater takes the place of the MAC in that the direction of the MII signals on the repeater is identical to that of the MAC. Note that the data terminal equipment (DTE) contains a PHY and a MAC device. The repeater and DTE are connected together via the physical medium via the appropriate PHY devices. In a preferred embodiment a single management unit on the repeater can serve as the management interface between the repeater 12 and all external PHY devices.
FIG. 2 is an embodiment of a managed repeater system. In the managed repeater system of FIG. 2 a MAC device 20 is usually required to reside with a repeater to allow a microprocessor 26 to extract statistics and to provide in-band management. The MAC device 20 is typically connected to one of the ports of the repeater. Two PHY devices 16 and 22 are necessary to provide the connection between the repeater core 14' and the MAC device 20.
One of the problems with the above-identified arrangements is that multiple PHYs are utilized even though they may not be necessary. These additional PHYs contribute to the overall cost of the system. It is possible to eliminate these PHYs by providing custom solutions. However, for systems which utilize standardized components this is not a viable alternative.
Therefore, what is desired is a system and method which minimize the number of PHYs required in a network environment, while not requiring a custom solution. The system and method should be compatible with existing systems and easily adaptable to such systems. In addition, the system should be cost effective and easily implemented utilizing existing manufacturing techniques. The present invention addresses such a need.